A couple weeks ago, GM released some photos showing the new design of the 2017 Sierra Denali 2500 HD. The photos prominently featured a hood scoop, but little was said as to the scoop's actual purpose, other than to say that it was “functional.” We know now what the scoop does, with a look at a Silverado 2500 HD thrown in for good measure.
The scoop is apparently part of a dual-circuit cold-air intake that will draw 60 percent of the intake air in. We don’t have any photos under the hood, but the system is described as a 180-degree elbow with a water separator function that will ensure the air entering the engine is as cool and dry as possible. The remaining air will go in through another intake on the front fender.